A tool clamping device, in particular a saw-tool clamping device, for a portable power tool is already known from EP 0 814 934 B1. The tool clamping device in this case has a clamping unit for clamping-in a machining tool, which comprises at least one movably mounted release element, at least for transferring the clamping unit into a release position, at least one clamping element, for generating a clamping-in force acting on the machining tool, at least when the machining tool is in a state in which it is connected to the clamping unit, and at least one movement-arresting element, for arresting at least one movement capability of the release element in at least one state.